By Matt Wilson, CISSP, Structured Systems Engineer II —
SASE is one of the hottest acronyms in IT. And one of the most misunderstood.
Despite being defined by Gartner in 2019, significant confusion remains about what Secure Access Service Edge (SASE) actually is, how it differs from related technologies, and what constitutes a mature implementation.
Even the most seasoned IT leaders can harbor some inaccurate notions about this seismic architectural shift in enterprise networking and security. Some of the most common misconceptions can lead to stalled projects, wasted budgets and security gaps that no one saw coming.
Before you make a move, be sure to separate fact from fiction. What follows is a clear breakdown of the 10 most persistent misconceptions, along with the corresponding realities based on current industry architecture.
Misconception 1: SASE is simply SD-WAN with cloud security added
Reality: SASE is a converged, cloud-native architecture that unifies networking and security into a single service delivered from a global edge fabric.
- SD-WAN provides the connectivity foundation
- SSE (Security Service Edge) provides cloud-delivered security controls
- True SASE combines both under a single policy engine, single data plane, and shared global infrastructure
Solutions that retain separate networking and security management planes, or require on-premises appliances for core functions, are hybrid offerings, not full SASE.
Misconception 2: SASE is a single product that can be purchased and installed
Reality: SASE is an architectural framework and delivery model, not a standalone product.
It consists of multiple integrated capabilities (SD-WAN, SWG, CASB, ZTNA, FWaaS, etc.) delivered as a unified cloud service. Organizations adopt SASE through subscription-based platforms rather than traditional hardware or software licenses.
Misconception 3: All vendors offering “SASE” provide equivalent capabilities
Reality: Significant architectural differences exist across vendors.
- Converged cloud-native platforms (e.g., Cato Networks, Netskope, Palo Alto Prisma Access) deliver unified networking and security from a single global fabric.
- SD-WAN-centric solutions add cloud security components to an existing routing platform.
- Security-centric (SSE-first) solutions provide strong cloud security with lighter or partnered SD-WAN capabilities.
Only the first category meets the full convergence requirements of the original SASE definition.
Misconception 4: SASE is primarily intended for remote workers
Reality: SASE addresses connectivity and security for all edge types — remote users, branch offices, cloud workloads, data centers, and devices.
It replaces traditional hub-and-spoke MPLS architecture with a distributed, identity-centric model regardless of location or connection type.
Misconception 5: SASE eliminates the need for firewalls
Reality: SASE shifts firewall functionality to the cloud (FWaaS) for north–south traffic, but local firewall or segmentation controls remain necessary for:
- East–west traffic within data centers
- OT/IoT environments
- Latency-sensitive applications
- Regulatory or air-gapped segments
Misconception 6: SASE requires all traffic to be routed through the cloud
Reality: Mature SASE implementations support intelligent, policy-based routing with local internet breakout for trusted applications (e.g., Microsoft 365, Zoom) and cloud inspection only for traffic requiring scrutiny.
Misconception 7: SASE immediately replaces all VPNs
Reality: SASE introduces Zero Trust Network Access (ZTNA), which is superior to traditional VPN for user-to-application access. However, site-to-site IPsec tunnels and legacy SSL VPNs are typically phased out over time rather than eliminated overnight.
Misconception 8: SASE can be deployed quickly across a large enterprise
Reality: Pilot deployments and small deployments can be completed in week(s). With some vendor platforms the core deployment can be implemented almost immediately. However, a full enterprise migration might involve:
- WAN topology redesign
- Identity provider integration
- Policy rationalization and migration
- Phased cutover from legacy appliances
Large organizations should plan for a multi-phase rollout, the timing of which is dependent on business requirements and ability of the team.
Misconception 9: SASE and SSE are interchangeable terms
Reality:
- SSE = the security components only (SWG, CASB, ZTNA, FWaaS, DLP)
- SASE = SSE + full SD-WAN convergence under a single platform
Many organizations adopt SSE as a first step before adding converged networking capabilities.
Misconception 10: SASE removes the need for any on-premises security controls
Reality: The majority of inspection and policy enforcement moves to the cloud, but on-premises controls typically remain for:
- Industrial control systems and OT
- High-volume east–west data center traffic
- Environments requiring physical or regulatory isolation
Hybrid cloud/on-premises security remains the most common production model.
Evaluation Checklist for SASE Offerings
When assessing vendor claims, confirm that the following capabilities exist natively within their single platform:
- Unified policy engine for networking and security
- Single-pass inspection
- Global private backbone with broad vendor-controlled PoP coverage
- Contextual decision-making (identity, device posture, risk scoring)
If any of these require separate products, partners, or on-premises appliances, the solution does not meet the full convergence standard of true SASE.
Understanding these distinctions enables more informed architectural decisions and more accurate vendor evaluations as organizations continue their journey toward a fully converged secure access service edge.
About the Author
Matt Wilson is a seasoned IT security engineer whose nearly two decades of professional expertise spans network infrastructure design, security architecture, implementation, and compliance auditing, making him a trusted advisor for organizations navigating complex IT infrastructure and security challenges.
He has designed and deployed secure networking environments for numerous clients, including national retail chains and multi-campus manufacturing companies. He has also provided critical emergency troubleshooting for myriad infrastructure issues. His skill set includes next-generation firewalls, web application firewalls, endpoint security, vulnerability management, risk assessments, disaster recovery planning, and more.
Whether crafting incident response playbooks or conducting security assessments, Matt brings a proven track record of safeguarding enterprise environments against evolving threats.